Research On Design And Simulation And Experiment Of Ultra-pure Water Bearingless Centrifugal Pump

Ultrapure water bearingless centrifugal pumps are mainly used in semiconductor,pharmaceutical,chemical and other high-cleanliness industries.Because bearingless centrifugal pumps have the advantages of non-contact,frictionless,low power consumption and low maintenance cost compared with traditional centrifugal pumps,especially for high-clean production environments,and have strong appeal.However,due to the production gap of domestic ultrapure water bearingless centrifugal pump products,the ultrapure water bearingless centrifugal pump used in the high clean industry basically relies on imports and is expensive.Based on this situation,In this paper,relevant research is carried out on the key parts of ultrapure water bearingless centrifugal pumps,and the main research as follows:First,the electromagnetic force on the rotor is analyzed and the cause of the levitation force is explained.According to Maxwell’s electromagnetic force formula,the expression of the suspension force is calculated by the piecewise integration method.And according to the eccentricity of the rotor,the expression of the electromagnetic torque is obtained by solving the imaginary displacement method.Next,design bearingless centrifugal pump systems.Comprehensively consider the structure,installation and cost and other aspects to determine the structure of the motor part.And by combining the traditional centrifugal pump design experience for hydraulic calculation,the impeller geometry design is completed.Finally,the 3D model of impeller and volute runner is builte by NX/UG.Then,the designed bearingless centrifugal pump was numerically simulated by ANSYS Fluent and ANSYS Maxwell.Fluent analyzes the effects of flow-head characteristics,flow-efficiency characteristics,and rotational speed on flow,head and efficiency.When the speed is low,the head drops faster;When the rotational speed is high,the inflection point of the head drop moves backwards.Research has found that flow,head,and efficiency all increase to varying degrees as the rotational speed increases.Finally,the radial force of the bearingless centrifugal pump is analyzed,and when the speed increases,the asymmetric radial force of the centrifugal pump also increases.When the speed is low,the asymmetric radial force tends to decrease as the flow rate increases in a reasonable range.Maxwell analyzed the characteristics of the motor part of a bearingless centrifugal pump under both no-load and load conditions,Through separate winding load analysis,the distribution design of torque winding and suspension winding is verified to be reasonable and meets the design expectations.Final,the construction of the bearingless centrifugal pump principle prototype was completed,including the centrifugal pump part,the motor part,the power module,the sensor and the digital signal processing system.In the last,the principle prototype system is tested,and the stator current detection and preliminary rotor suspension are realized,and it proves that the scheme designed in this paper is feasible.